The Tor Browser: dom/src/storage/DOMStorageCache.h@b8a032363ba2 (annotated)

dom/src/storage/DOMStorageCache.h@b8a032363ba2 (annotated)

dom/src/storage/DOMStorageCache.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef nsDOMStorageCache_h___
 #define nsDOMStorageCache_h___
 #include "nsIURI.h"
 #include "nsIPrincipal.h"
 #include "nsITimer.h"
 #include "nsString.h"
 #include "nsDataHashtable.h"
 #include "nsHashKeys.h"
 #include "mozilla/Monitor.h"
 #include "mozilla/Telemetry.h"
 #include "nsAutoPtr.h"
 namespace mozilla {
 namespace dom {
 class DOMStorage;
 class DOMStorageUsage;
 class DOMStorageManager;
 class DOMStorageDBBridge;
 // Interface class on which only the database or IPC may call.
 // Used to populate the cache with DB data.
 class DOMStorageCacheBridge
 {
 public:
   NS_IMETHOD_(MozExternalRefCountType) AddRef(void);
   NS_IMETHOD_(void) Release(void);
   virtual ~DOMStorageCacheBridge() {}
   // The scope (origin) in the database usage format (reversed)
   virtual const nsCString& Scope() const = 0;
   // Whether the cache is already fully loaded
   virtual bool Loaded() = 0;
   // How many items has so far been loaded into the cache, used
   // for optimization purposes
   virtual uint32_t LoadedCount() = 0;
   // Called by the database to load a key and its value to the cache
   virtual bool LoadItem(const nsAString& aKey, const nsString& aValue) = 0;
   // Called by the database after all keys and values has been loaded
   // to this cache
   virtual void LoadDone(nsresult aRv) = 0;
   // Use to synchronously wait until the cache gets fully loaded with data,
   // this method exits after LoadDone has been called
   virtual void LoadWait() = 0;
 protected:
   ThreadSafeAutoRefCnt mRefCnt;
   NS_DECL_OWNINGTHREAD
 };
 // Implementation of scope cache that is responsible for preloading data
 // for persistent storage (localStorage) and hold data for non-private,
 // private and session-only cookie modes.  It is also responsible for
 // persisting data changes using the database, works as a write-back cache.
 class DOMStorageCache : public DOMStorageCacheBridge
 {
 public:
   NS_IMETHOD_(void) Release(void);
   DOMStorageCache(const nsACString* aScope);
   virtual ~DOMStorageCache();
   void Init(DOMStorageManager* aManager, bool aPersistent,
             nsIURI* aFirstPartyIsolationURI, nsIPrincipal* aPrincipal,
             const nsACString& aQuotaScope);
   // Copies all data from the other storage.
   void CloneFrom(const DOMStorageCache* aThat);
   // Starts async preload of this cache if it persistent and not loaded.
   void Preload();
   // Keeps the cache alive (i.e. present in the manager's hash table) for a time.
   void KeepAlive();
   // The set of methods that are invoked by DOM storage web API.
   // We are passing the DOMStorage object just to let the cache
   // read properties like mPrivate and mSessionOnly.
   // Get* methods return error when load from the database has failed.
   nsresult GetLength(const DOMStorage* aStorage, uint32_t* aRetval);
   nsresult GetKey(const DOMStorage* aStorage, uint32_t index, nsAString& aRetval);
   nsresult GetItem(const DOMStorage* aStorage, const nsAString& aKey, nsAString& aRetval);
   nsresult SetItem(const DOMStorage* aStorage, const nsAString& aKey, const nsString& aValue, nsString& aOld);
   nsresult RemoveItem(const DOMStorage* aStorage, const nsAString& aKey, nsString& aOld);
   nsresult Clear(const DOMStorage* aStorage);
   nsTArray<nsString>* GetKeys(const DOMStorage* aStorage);
   nsIURI* FirstPartyIsolationURI() const { return mFirstPartyIsolationURI; }
   // Whether the principal equals principal the cache was created for
   bool CheckPrincipal(nsIPrincipal* aPrincipal) const;
   nsIPrincipal* Principal() const { return mPrincipal; }
   // Starts the database engine thread or the IPC bridge
   static DOMStorageDBBridge* StartDatabase();
   static DOMStorageDBBridge* GetDatabase();
   // Stops the thread and flushes all uncommited data
   static nsresult StopDatabase();
   // DOMStorageCacheBridge
   virtual const nsCString& Scope() const { return mScope; }
   virtual bool Loaded() { return mLoaded; }
   virtual uint32_t LoadedCount();
   virtual bool LoadItem(const nsAString& aKey, const nsString& aValue);
   virtual void LoadDone(nsresult aRv);
   virtual void LoadWait();
   // Cache keeps 3 sets of data: regular, private and session-only.
   // This class keeps keys and values for a set and also caches
   // size of the data for quick per-origin quota checking.
   class Data
   {
   public:
     Data() : mOriginQuotaUsage(0) {}
     int64_t mOriginQuotaUsage;
     nsDataHashtable<nsStringHashKey, nsString> mKeys;
   };
 public:
   // Number of data sets we keep: default, private, session
   static const uint32_t kDataSetCount = 3;
 private:
   // API to clear the cache data, this is invoked by chrome operations
   // like cookie deletion.
   friend class DOMStorageManager;
   static const uint32_t kUnloadDefault = 1 << 0;
   static const uint32_t kUnloadPrivate = 1 << 1;
   static const uint32_t kUnloadSession = 1 << 2;
   static const uint32_t kUnloadComplete =
     kUnloadDefault | kUnloadPrivate | kUnloadSession;
 #ifdef DOM_STORAGE_TESTS
   static const uint32_t kTestReload    = 1 << 15;
 #endif
   void UnloadItems(uint32_t aUnloadFlags);
 private:
   // Synchronously blocks until the cache is fully loaded from the database
   void WaitForPreload(mozilla::Telemetry::ID aTelemetryID);
   // Helper to get one of the 3 data sets (regular, private, session)
   Data& DataSet(const DOMStorage* aStorage);
   // Whether the storage change is about to persist
   bool Persist(const DOMStorage* aStorage) const;
   // Changes the quota usage on the given data set if it fits the quota.
   // If not, then false is returned and no change to the set must be done.
   bool ProcessUsageDelta(uint32_t aGetDataSetIndex, const int64_t aDelta);
   bool ProcessUsageDelta(const DOMStorage* aStorage, const int64_t aDelta);
 private:
   // When a cache is reponsible for its life time (in case of localStorage data
   // cache) we need to refer our manager since removal of the cache from the hash
   // table is handled in the destructor by call to the manager.
   // Cache could potentially overlive the manager, hence the hard ref.
   nsRefPtr<DOMStorageManager> mManager;
   // Reference to the usage counter object we check on for eTLD+1 quota limit.
   // Obtained from the manager during initialization (Init method).
   nsRefPtr<DOMStorageUsage> mUsage;
   // Timer that holds this cache alive for a while after it has been preloaded.
   nsCOMPtr<nsITimer> mKeepAliveTimer;
   // The first party URI associated with this cache.
   nsCOMPtr<nsIURI> mFirstPartyIsolationURI;
   // Principal the cache has been initially created for, this is used only
   // for sessionStorage access checks since sessionStorage objects are strictly
   // scoped by a principal.  localStorage objects on the other hand are scoped by
   // origin only.
   nsCOMPtr<nsIPrincipal> mPrincipal;
   // The scope this cache belongs to in the "DB format", i.e. reversed
   nsCString mScope;
   // The eTLD+1 scope used to count quota usage.
   nsCString mQuotaScope;
   // Non-private Browsing, Private Browsing and Session Only sets.
   Data mData[kDataSetCount];
   // This monitor is used to wait for full load of data.
   mozilla::Monitor mMonitor;
   // Flag that is initially false.  When the cache is about to work with
   // the database (i.e. it is persistent) this flags is set to true after
   // all keys and coresponding values are loaded from the database.
   // This flag never goes from true back to false.
   bool mLoaded;
   // Result of load from the database.  Valid after mLoaded flag has been set.
   nsresult mLoadResult;
   // Init() method has been called
   bool mInitialized : 1;
   // This cache is about to be bound with the database (i.e. it has
   // to load from the DB first and has to persist when modifying the
   // default data set.)
   bool mPersistent : 1;
   // - False when the session-only data set was never used.
   // - True after access to session-only data has been made for the first time.
   // We also fill session-only data set with the default one at that moment.
   // Drops back to false when session-only data are cleared from chrome.
   bool mSessionOnlyDataSetActive : 1;
   // Whether we have already captured state of the cache preload on our first access.
   bool mPreloadTelemetryRecorded : 1;
   // DOMStorageDBThread on the parent or single process,
   // DOMStorageDBChild on the child process.
   static DOMStorageDBBridge* sDatabase;
   // False until we shut the database down.
   static bool sDatabaseDown;
 };
 // DOMStorageUsage
 // Infrastructure to manage and check eTLD+1 quota
 class DOMStorageUsageBridge
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DOMStorageUsageBridge)
   virtual const nsCString& Scope() = 0;
   virtual void LoadUsage(const int64_t aUsage) = 0;
 protected:
   // Protected destructor, to discourage deletion outside of Release():
   virtual ~DOMStorageUsageBridge() {}
 };
 class DOMStorageUsage : public DOMStorageUsageBridge
 {
 public:
   DOMStorageUsage(const nsACString& aScope);
   bool CheckAndSetETLD1UsageDelta(uint32_t aDataSetIndex, int64_t aUsageDelta);
 private:
   virtual const nsCString& Scope() { return mScope; }
   virtual void LoadUsage(const int64_t aUsage);
   nsCString mScope;
   int64_t mUsage[DOMStorageCache::kDataSetCount];
 };
 } // ::dom
 } // ::mozilla
 #endif

The Tor Browser / annotate

dom/src/storage/DOMStorageCache.h@b8a032363ba2 (annotated)

dom/src/storage/DOMStorageCache.h